This invention relates to an improved placement for the valve in an inflatable, multi-ply bag. This invention is particularly concerned with the valve placement in dunnage bags and the like.
Multi-ply, inflatable bags as shoring devices and as containers for liquids are well known. See, for example, U.S. Pat. Nos. 2,674,206, 3,072,270, 3,204,825, 3,365,116, 3,462,027, 3,554,135, 3,730,240 and 3,747,954 and Canadian Pat. No. 703,322. Typically, such multi-ply, inflatable bags have included a relatively flexible, inner, inflatable bladder, a valve, and a relatively strong and rigid, outer, protective shell enclosing the bladder and valve. Generally, the protective shells have included folds adapted to allow the bags to lie flat when the bladders are uninflated and to permit the shells to expand when the bladders are inflated. See, for example, U.S. Pat. Nos. 3,072,270, 3,365,116 and 3,462,027 and Canadian Pat. No. 702,322.
When multi-ply bags have been intended for use as shoring devices, the protective shells have typically been made of relatively strong but inexpensive, abrasion and puncture resistant materials, such as burlap, rayon fabric and kraft paper, as well as plastics, such as polypropylene, and multi-layer laminates of such materials. In such multi-ply bags, the inner bladders have typically been made of inexpensive, thin wall, rubber or plastic sheet materials, such as polyethylene.
On the other hand, when the multi-ply bags have been intended for use as containers for liquids, the bladders have usually been made of a relatively strong and thick, rubber or plastic material, which is inert to the contents of the bladder and which provides some barrier properties. In such bags, the protective shells also have typically been formed from relatively strong and thick, rubber or plastic materials which are both abrasion and puncture resistant as well as leak resistant.
Such multi-ply, inflatable bags have provided relatively inexpensive and durable, liquid containers and shoring devices. However, the valves in such bags have tended to be relatively prone to damage from the mishandling or abuse of the bags. The valves have frequently been broken when the protective shells have been forcefully scuffed, rubbed or struck in the area of the valve. The valves have also been quite susceptible to being crushed, particularly when uninflated bags have been stored in stacks. The valves in dunnage bags have been especially prone to being damaged by being scuffed, rubbed, struck or crushed.
There has been an unfilled need therefore for an improved, multi-ply, inflatable bag in which the valve is more resistant to failure due to abuse or rough handling of the multi-ply bag in the area of the valve.